Load control system having a visible light sensor

ABSTRACT

A sensor for sensing environmental characteristics of a space may include a visible light sensing circuit for recording an image of the space and a control circuit responsive to the visible light sensing circuit. The control circuit may detect an occupancy or vacancy condition in the space in response to the visible light sensing circuit, and measure a light level in the space in response to the visible light sensing circuit. The control circuit may also include a low-energy occupancy sensing circuit for detecting an occupancy condition in the space. The control circuit may disable the visible light sensing circuit when the space is vacant. The control circuit may detect an occupancy condition in the space in response to the low-energy occupancy sensing circuit and subsequently enable the visible light sensing circuit. The visible light sensor may be configured in a way that protects the privacy of the occupants of the space.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/374,928, filed Dec. 9, 2016, which claims priority from U.S.Provisional Patent Application No. 62/266,370, filed Dec. 11, 2015, thedisclosures of which are hereby incorporated herein in their entireties.

BACKGROUND

A user environment, such as a residence or an office building, forexample, may be configured using various types of load control systems.A lighting control system may be used to control the lighting loadsproviding artificial light in the user environment. A motorized windowtreatment control system may be used to control the natural lightprovided to the user environment. An HVAC system may be used to controlthe temperature in the user environment.

Each load control system may include various control devices, includinginput devices and load control devices. The load control devices mayreceive digital messages, which may include load control instructions,for controlling an electrical load from one or more of the inputdevices. The load control devices may be capable of directly controllingan electrical load. The input devices may be capable of indirectlycontrolling the electrical load via the load control device.

Examples of load control devices may include lighting control devices(e.g., a dimmer switch, an electronic switch, a ballast, or alight-emitting diode (LED) driver), a motorized window treatment, atemperature control device (e.g., a thermostat), an AC plug-in loadcontrol device, and/or the like. Examples of input devices may includeremote control devices, occupancy sensors, daylight sensors, glaresensors, color temperature sensors, temperature sensors, and/or thelike. Remote control devices may receive user input for performing loadcontrol. Occupancy sensors may include infrared (IR) sensors fordetecting occupancy/vacancy of a space based on movement of the users.Daylight sensors may detect a daylight level received within a space.Glare sensors may be positioned facing outside of a building (e.g., on awindow or exterior of a building) to identify the position of the sunwhen in view of the glare sensor. Color temperature sensor determinesthe color temperature within a user environment based on the wavelengthsand/or frequencies of light. Temperature sensors may detect the currenttemperature of the space.

As described herein, current load control systems implement many inputdevices, including a number of different sensors. The use of many inputdevices causes the load control systems to take readings from multipledifferent types of devices and control loads based on many differenttypes of input. Additionally, many of these devices communicatewirelessly over the same wireless communication network, which maycreate congestion on the network due to the number of devices that maybe communicating at the same time.

The input devices in current load control systems may also beinefficient for performing their independent functions in the loadcontrol systems. For example, current load control systems may receiveinput from a glare sensor that indicates that glare is being receivedfrom the sun, but load control systems may attempt to reduce oreliminate the amount of glare within the user environment usingprediction algorithms to predict the portions of the user environmentthat are being affected by glare. Attempting to reduce or eliminate theamount of glare within the user environment using these predictionalgorithms may be unreliable.

The daylight sensors and the color temperature sensors in the loadcontrol systems may also be inefficient for gathering accurateinformation for performing load control. Current use of daylight sensorsand color temperature sensors rely on the accuracy of the location ofthe sensor for detecting how the intensity of light affects the userenvironment. It may be desirable to have more accurate ways ofdetermining how the actual intensity and color of light provided withinthe user environment affects a user within the environment.

As the occupancy/vacancy sensor generally senses the presence or absenceof a person within the user environment using passive infra-red (PIR)technology, the occupancy/vacancy sensor may fail to detect theoccupancy of a room due to the lack of movement by a user. Theoccupancy/vacancy sensor senses the presence of a person using the heatmovement of the person. The vacancy sensor determines a vacancycondition within the user environment in the absence of the heatmovement of a person for a specified timeout period. Theoccupancy/vacancy sensor may detect the presence or absence of a userwithin the user environment, but the sensor may fail to provide accurateresults. For example, the occupancy/vacancy sensor may detect other heatsources within a user environment and inaccurately determine that theheat sources are emanating from a person. Further, the occupancy/vacancysensor is unable to identify a person that is not moving, or that ismaking minor movements, within the user environment. Thus, it may bedesirable to otherwise determine occupancy/vacancy within a userenvironment.

As complex load control systems generally include many different typesof input devices for gathering information about a load controlenvironment, the processing and communicating of information in suchsystems can be inefficient. Additionally, as the information collectedby many input devices may be inaccurate, the control of loads accordingto such information may also be inaccurate.

SUMMARY

The present disclosure relates to a load control system for controllingthe amount of power delivered to one or more electrical load, and moreparticularly, to a load control system having a visible light sensor fordetecting occupancy and/or vacancy conditions in a space.

As described herein, a sensor for sensing environmental characteristicsof a space comprises a visible light sensing circuit configured torecord an image of the space and a control circuit responsive to thevisible light sensing circuit. The control circuit may be configured todetect at least one of an occupancy condition and a vacancy condition inthe space in response to the visible light sensing circuit, and tomeasure a light level in the space in response to the visible lightsensing circuit.

The visible light sensor may perform differently depending on the modein which the visible light sensor is operating. For example, the visiblelight sensor may detect and/or adjust an environmental characteristicwithin a space based on the mode in which the visible light sensor isoperating. The visible light sensor may operate in a particular mode fora period of time and/or the visible light sensor may switch from onemode to another mode after the same, or different, period of time. Themodes in which the visible light sensor may operate may include asunlight glare mode, a daylighting mode, a color temperature mode, anoccupancy/vacancy mode, etc.

The control circuit may be configured to sense a first environmentalcharacteristic of the space by applying a first mask to focus on a firstregion of interest of the image, and to sense a second environmentalcharacteristic of the space by applying a second mask to focus on asecond region of interest of the image. The control circuit may beconfigured to apply the first mask to focus on the first region ofinterest of the image in order to detect at least one of an occupancycondition and a vacancy condition in the space. The control circuit maybe configured to apply the second mask to focus on the second region ofinterest of the image in order to measure a light level in the space.

The control circuit may be configured to perform a number of sequentialsensor events for sensing a plurality of environmental characteristicsin response to the image. Each sensor event may be characterized by oneof the plurality of environmental characteristics to detect during thesensor event and a respective mask. The control circuit may beconfigured to perform one of the sensor events to sense the respectiveenvironmental characteristic by applying the respective mask to theimage to focus on a region of interest and process the portion of theimage in the region of interested using to a predetermined algorithm forsensing the respective environmental characteristic.

The control circuit may further comprise a low-energy occupancy sensingcircuit configured to detect an occupancy condition in the space. Thecontrol circuit may be configured to disable the visible light sensingcircuit when the space is vacant. The control circuit may be configuredto detect an occupancy condition in the space in response to thelow-energy occupancy sensing circuit and to subsequently enable thevisible light sensing circuit. The control circuit may be configured todetect that a vacancy condition in the space in response to the visiblelight sensor.

Methods of configuring a visible light sensor mounted in a space arealso described herein. The visible light sensor may be configured in away that protects the privacy of the occupants of the space. The visiblelight sensor may be installed at a location at which the visible lightsensor can record an image of the space. The visible light sensorconfigured to transmit and receive digital message via a firstcommunication link during normal operation.

A first method of configuring a visible light sensor may comprise: (1)recording an image of the space by the visible light sensor; (2)executing a configuration software on the visible light sensor totransmit a digital representation of the image to a network device via asecond communication link; (3) setting at least one configurationparameter of the visible light sensor at the network device using thedigital representation of the image; (4) transmitting the at least oneconfiguration parameter to the visible light sensor; and (5)subsequently installing normal operation software in place of theconfiguration software, wherein the visible light sensor is not able totransmit digital messages via the second communication link whileexecuting the normal operation software during normal operation.

A second method of configuring a visible light sensor may comprise: (1)installing a configuration module in the visible light sensor, theconfiguration module enabling the visible light sensor to transmit andreceive digital messages via a second communication link; (2) recordingan image of the space by the visible light sensor; (3) transmitting adigital representation of the image from the visible light sensor to anetwork device via the second communication link while the configurationmodule in installed in the visible light sensor; (4) setting at leastone configuration parameter of the visible light sensor at the networkdevice using the digital representation of the image; (5) transmittingthe at least one configuration parameter to the visible light sensor;and (6) uninstalling the configuration module from the visible lightsensor to prevent the visible light sensor from subsequentlytransmitting digital messages via the second communication link duringnormal operation.

A third method of configuring a visible light sensor may comprise: (1)installing a configuration sensor at the location at which the visiblelight sensor is to be installed; (2) recording an image of the space bythe configuration sensor; (3) transmit a digital representation of theimage from the configuration sensor to a network device via a secondcommunication link; (4) setting at least one configuration parameter ofthe visible light sensor at the network device using the digitalrepresentation of the image; (5) uninstalling the configuration sensor;(6) installing the visible light sensor at the location at which thevisible light sensor can record an image of the space; and (7)transmitting the at least one configuration parameter to the visiblelight sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simple diagram of an example load control system having avisible light sensor.

FIGS. 2A-2G show simplified example images of a room that may berecorded by a camera of a visible light sensor.

FIG. 3 is a simplified block diagram of an example visible light sensor.

FIGS. 4 and 5 show flowcharts of example control procedures that may beexecuted by a control circuit of a visible light sensor.

FIG. 6 shows a flowchart of an example vacancy time procedure that maybe executed by a control circuit of a visible light sensor.

FIG. 7 shows a flowchart of an example sensor event procedure that maybe executed by a control circuit of a visible light sensor.

FIGS. 8 and 9 show flowcharts of example glare detection procedures thatmay be executed by a control circuit of a visible light sensor.

FIG. 10 shows a flowchart of an example configuration procedure for avisible light sensor using a special configuration software.

FIG. 11 shows a flowchart of an example configuration procedure for avisible light sensor using a removable configuration module.

FIG. 12 shows a flowchart of an example configuration procedure for avisible light sensor using a special configuration sensor.

DETAILED DESCRIPTION

FIG. 1 is a simple diagram of an example load control system 100 forcontrolling the amount of power delivered from an alternating-current(AC) power source (not shown) to one or more electrical loads. The loadcontrol system 100 may be installed in a room 102 of a building. Theload control system 100 may comprise a plurality of control devicesconfigured to communicate with each other via wireless signals, e.g.,radio-frequency (RF) signals 108. Alternatively or additionally, theload control system 100 may comprise a wired digital communication linkcoupled to one or more of the control devices to provide forcommunication between the load control devices. The control devices ofthe load control system 100 may comprise a number of control-sourcedevices (e.g., input devices operable to transmit digital messages inresponse to user inputs, occupancy/vacancy conditions, changes inmeasured light intensity, etc.) and a number of control-target devices(e.g., load control devices operable to receive digital messages andcontrol respective electrical loads in response to the received digitalmessages). A single control device of the load control system 100 mayoperate as both a control-source and a control-target device.

The control-source devices may be configured to transmit digitalmessages directly to the control-target devices. In addition, the loadcontrol system 100 may comprise a system controller 110 (e.g., a centralprocessor or load controller) operable to communicate digital messagesto and from the control devices (e.g., the control-source devices and/orthe control-target devices). For example, the system controller 110 maybe configured to receive digital messages from the control-sourcedevices and transmit digital messages to the control-target devices inresponse to the digital messages received from the control-sourcedevices. The control-source and control-target devices and the systemcontroller 110 may be configured to transmit and receive the RF signals108 using a proprietary RF protocol, such as the ClearConnect® protocol.Alternatively, the RF signals 108 may be transmitted using a differentRF protocol, such as, a standard protocol, for example, one of WIFI,ZIGBEE, Z-WAVE, KNX-RF, ENOCEAN RADIO protocols, or a differentproprietary protocol.

The load control system 100 may comprise one or more load controldevices, e.g., a dimmer switch 120 for controlling a lighting load 122.The dimmer switch 120 may be adapted to be wall-mounted in a standardelectrical wallbox. The dimmer switch 120 may comprise a tabletop orplug-in load control device. The dimmer switch 120 may comprise a toggleactuator (e.g., a button) and an intensity adjustment actuator (e.g., arocker switch). Actuations (e.g., successive actuations) of the toggleactuator may toggle (e.g., turn off and on) the lighting load 122.Actuations of an upper portion or a lower portion of the intensityadjustment actuator may respectively increase or decrease the amount ofpower delivered to the lighting load 122 and thus increase or decreasethe intensity of the receptive lighting load from a minimum intensity(e.g., approximately 1%) to a maximum intensity (e.g., approximately100%). The dimmer switch 120 may comprise a plurality of visualindicators, e.g., light-emitting diodes (LEDs), which may be arranged ina linear array and are illuminated to provide feedback of the intensityof the lighting load 122. Examples of wall-mounted dimmer switches aredescribed in greater detail in U.S. Pat. No. 5,248,919, issued Sep. 29,1993, entitled LIGHTING CONTROL DEVICE, and U.S. Patent ApplicationPublication No. 2014/0132475, published May 15, 2014, entitled WIRELESSLOAD CONTROL DEVICE, the entire disclosures of which are herebyincorporated by reference.

The dimmer switch 120 may be configured to wirelessly receive digitalmessages via the RF signals 108 (e.g., from the system controller 110)and to control the lighting load 122 in response to the received digitalmessages. Examples of dimmer switches operable to transmit and receivedigital messages is described in greater detail in commonly-assignedU.S. patent application Ser. No. 12/033,223, filed Feb. 19, 2008,entitled COMMUNICATION PROTOCOL FOR A RADIO-FREQUENCY LOAD CONTROLSYSTEM, the entire disclosure of which is hereby incorporated byreference.

The load control system 100 may comprise one or more remotely-locatedload control devices, such as a light-emitting diode (LED) driver 130for driving an LED light source 132 (e.g., an LED light engine). The LEDdriver 130 may be located remotely, for example, in or adjacent to thelighting fixture of the LED light source 132. The LED driver 130 may beconfigured to receive digital messages via the RF signals 108 (e.g.,from the system controller 110) and to control the LED light source 132in response to the received digital messages. The LED driver 130 may beconfigured to adjust the color temperature of the LED light source 132in response to the received digital messages. Examples of LED driversconfigured to control the color temperature of LED light sources aredescribed in greater detail in commonly-assigned U.S. Patent ApplicationPublication No. 2014/0312777, filed Oct. 23, 2014, entitled SYSTEMS ANDMETHODS FOR CONTROLLING COLOR TEMPERATURE, the entire disclosure ofwhich is hereby incorporated by reference. The load control system 100may further comprise other types of remotely-located load controldevices, such as, for example, electronic dimming ballasts for drivingfluorescent lamps.

The load control system 100 may comprise a plug-in load control device140 for controlling a plug-in electrical load, e.g., a plug-in lightingload (such as a floor lamp 142 or a table lamp) and/or an appliance(such as a television or a computer monitor). For example, the floorlamp 142 may be plugged into the plug-in load control device 140. Theplug-in load control device 140 may be plugged into a standardelectrical outlet 144 and thus may be coupled in series between the ACpower source and the plug-in lighting load. The plug-in load controldevice 140 may be configured to receive digital messages via the RFsignals 108 (e.g., from the system controller 110) and to turn on andoff or adjust the intensity of the floor lamp 142 in response to thereceived digital messages.

Alternatively or additionally, the load control system 100 may comprisecontrollable receptacles for controlling plug-in electrical loadsplugged into the receptacles. The load control system 100 may compriseone or more load control devices or appliances that are able to directlyreceive the wireless signals 108 from the system controller 110, such asa speaker 146 (e.g., part of an audio/visual or intercom system), whichis able to generate audible sounds, such as alarms, music, intercomfunctionality, etc.

The load control system 100 may comprise one or more daylight controldevices, e.g., motorized window treatments 150, such as motorizedcellular shades, for controlling the amount of daylight entering theroom 102. Each motorized window treatments 150 may comprise a windowtreatment fabric 152 hanging from a headrail 154 in front of arespective window 104. Each motorized window treatment 150 may furthercomprise a motor drive unit (not shown) located inside of the headrail154 for raising and lowering the window treatment fabric 152 forcontrolling the amount of daylight entering the room 102. The motordrive units of the motorized window treatments 150 may be configured toreceive digital messages via the RF signals 108 (e.g., from the systemcontroller 110) and adjust the position of the respective windowtreatment fabric 152 in response to the received digital messages. Theload control system 100 may comprise other types of daylight controldevices, such as, for example, a cellular shade, a drapery, a Romanshade, a Venetian blind, a Persian blind, a pleated blind, a tensionedroller shade systems, an electrochromic or smart window, and/or othersuitable daylight control device. Examples of battery-powered motorizedwindow treatments are described in greater detail in U.S. Pat. No.8,950,461, issued Feb. 10, 2015, entitled MOTORIZED WINDOW TREATMENT,and U.S. Patent Application Publication No. 2014/0305602, published Oct.16, 2014, entitled INTEGRATED ACCESSIBLE BATTERY COMPARTMENT FORMOTORIZED WINDOW TREATMENT, the entire disclosures of which are herebyincorporated by reference.

The load control system 100 may comprise one or more temperature controldevices, e.g., a thermostat 160 for controlling a room temperature inthe room 102. The thermostat 160 may be coupled to a heating,ventilation, and air conditioning (HVAC) system 162 via a control link(e.g., an analog control link or a wired digital communication link).The thermostat 160 may be configured to wirelessly communicate digitalmessages with a controller of the HVAC system 162. The thermostat 160may comprise a temperature sensor for measuring the room temperature ofthe room 102 and may control the HVAC system 162 to adjust thetemperature in the room to a setpoint temperature. The load controlsystem 100 may comprise one or more wireless temperature sensors (notshown) located in the room 102 for measuring the room temperatures. TheHVAC system 162 may be configure to turn a compressor on and off forcooling the room 102 and to turn a heating source on and off for heatingthe rooms in response to the control signals received from thethermostat 160. The HVAC system 162 may be configured to turn a fan ofthe HVAC system on and off in response to the control signals receivedfrom the thermostat 160. The thermostat 160 and/or the HVAC system 162may be configured to control one or more controllable dampers to controlthe air flow in the room 102. The thermostat 160 may be configured toreceive digital messages via the RF signals 108 (e.g., from the systemcontroller 110) and adjust heating, ventilation, and cooling in responseto the received digital messages.

The load control system 100 may comprise one or more other types of loadcontrol devices, such as, for example, a screw-in luminaire including adimmer circuit and an incandescent or halogen lamp; a screw-in luminaireincluding a ballast and a compact fluorescent lamp; a screw-in luminaireincluding an LED driver and an LED light source; an electronic switch,controllable circuit breaker, or other switching device for turning anappliance on and off; a plug-in load control device, controllableelectrical receptacle, or controllable power strip for controlling oneor more plug-in loads; a motor control unit for controlling a motorload, such as a ceiling fan or an exhaust fan; a drive unit forcontrolling a motorized window treatment or a projection screen;motorized interior or exterior shutters; a thermostat for a heatingand/or cooling system; a temperature control device for controlling asetpoint temperature of an HVAC system; an air conditioner; acompressor; an electric baseboard heater controller; a controllabledamper; a variable air volume controller; a fresh air intake controller;a ventilation controller; a hydraulic valves for use radiators andradiant heating system; a humidity control unit; a humidifier; adehumidifier; a water heater; a boiler controller; a pool pump; arefrigerator; a freezer; a television or computer monitor; a videocamera; an audio system or amplifier; an elevator; a power supply; agenerator; an electric charger, such as an electric vehicle charger; andan alternative energy controller.

The load control system 100 may comprise one or more input devices,e.g., such as a remote control device 170 and a visible light sensor180. The input devices may be fixed or movable input devices. The systemcontroller 110 may be configured to transmit one or more digitalmessages to the load control devices (e.g., the dimmer switch 120, theLED driver 130, the plug-in load control device 140, the motorizedwindow treatments 150, and/or the thermostat 160) in response to thedigital messages received from the remote control device 170 and thevisible light sensor 180. The remote control device 170 and the visiblelight sensor 180 may be configured to transmit digital messages directlyto the dimmer switch 120, the LED driver 130, the plug-in load controldevice 140, the motorized window treatments 150, and the temperaturecontrol device 160.

The remote control device 170 may be configured to transmit digitalmessages via the RF signals 108 to the system controller 110 (e.g.,directly to the system controller) in response to an actuation of one ormore buttons of the remote control device. For example, the remotecontrol device 170 may be battery-powered. The load control system 100may comprise other types of input devices, such as, for example,temperature sensors, humidity sensors, radiometers, cloudy-day sensors,shadow sensors, pressure sensors, smoke detectors, carbon monoxidedetectors, air-quality sensors, motion sensors, security sensors,proximity sensors, fixture sensors, partition sensors, keypads,multi-zone control units, slider control units, kinetic or solar-poweredremote controls, key fobs, cell phones, smart phones, tablets, personaldigital assistants, personal computers, laptops, timeclocks,audio-visual controls, safety devices, power monitoring devices (e.g.,such as power meters, energy meters, utility submeters, utility ratemeters, etc.), central control transmitters, residential, commercial, orindustrial controllers, and/or any combination thereof.

The system controller 110 may be coupled to a network, such as awireless or wired local area network (LAN), e.g., for access to theInternet. The system controller 110 may be wirelessly connected to thenetwork, e.g., using Wi-Fi technology. The system controller 110 may becoupled to the network via a network communication bus (e.g., anEthernet communication link). The system controller 110 may beconfigured to communicate via the network with one or more networkdevices, e.g., a mobile device 190, such as, a personal computing deviceand/or a wearable wireless device. The mobile device 190 may be locatedon an occupant 192, for example, may be attached to the occupant's bodyor clothing or may be held by the occupant. The mobile device 190 may becharacterized by a unique identifier (e.g., a serial number or addressstored in memory) that uniquely identifies the mobile device 190 andthus the occupant 192. Examples of personal computing devices mayinclude a smart phone (for example, an iPhone® smart phone, an Android®smart phone, or a Blackberry® smart phone), a laptop, and/or a tabletdevice (for example, an iPad® hand-held computing device). Examples ofwearable wireless devices may include an activity tracking device (suchas a FitBit® device, a Misfit® device, and/or a Sony Smartband® device),a smart watch, smart clothing (e.g., OMsignal® smartwear, etc.), and/orsmart glasses (such as Google Glass® eyewear). In addition, the systemcontroller 110 may be configured to communicate via the network with oneor more other control systems (e.g., a building management system, asecurity system, etc.).

The mobile device 190 may be configured to transmit digital messages tothe system controller 110, for example, in one or more Internet Protocolpackets. For example, the mobile device 190 may be configured totransmit digital messages to the system controller 110 over the LANand/or via the internet. The mobile device 190 may be configured totransmit digital messages over the internet to an external service(e.g., If This Then That (IFTTT®) service), and then the digitalmessages may be received by the system controller 110. The mobile device190 may transmit and receive RF signals 109 via a Wi-Fi communicationlink, a Wi-MAX communications link, a Bluetooth communications link, anear field communication (NFC) link, a cellular communications link, atelevision white space (TVWS) communication link, or any combinationthereof. Alternatively or additionally, the mobile device 190 may beconfigured to transmit RF signals according to the proprietary protocol.The load control system 100 may comprise other types of network devicescoupled to the network, such as a desktop personal computer, a Wi-Fi orwireless-communication-capable television, or any other suitableInternet-Protocol-enabled device. Examples of load control systemsoperable to communicate with mobile and/or network devices on a networkare described in greater detail in commonly-assigned U.S. PatentApplication Publication No. 2013/0030589, published Jan. 31, 2013,entitled LOAD CONTROL DEVICE HAVING INTERNET CONNECTIVITY, the entiredisclosure of which is hereby incorporated by reference.

The system controller 110 may be configured to determine the location ofthe mobile device 190 and/or the occupant 192. The system controller 110may be configured to control (e.g., automatically control) the loadcontrol devices (e.g., the dimmer switch 120, the LED driver 130, theplug-in load control device 140, the motorized window treatments 150,and/or the temperature control device 160) in response to determiningthe location of the mobile device 190 and/or the occupant 192. One ormore of the control devices of the load control system 100 may transmitbeacon signals, for example, RF beacon signals transmitted using ashort-range and/or low-power RF technology, such as Bluetoothtechnology. The load control system 100 may also comprise at least onebeacon transmitting device 194 for transmitting the beacon signals. Themobile device 190 may be configured to receive a beacon signal whenlocated near a control device that is presently transmitting the beaconsignal. A beacon signal may comprise a unique identifier identifying thelocation of the load control device that transmitted the beacon signal.Since the beacon signal may be transmitted using a short-range and/orlow-power technology, the unique identifier may indicate the approximatelocation of the mobile device 190. The mobile device 190 may beconfigured to transmit the unique identifier to the system controller110, which may be configured to determine the location of the mobiledevice 190 using the unique identifier (e.g., using data stored inmemory or retrieved via the Internet). An example of a load controlsystem for controlling one or more electrical loads in response to theposition of a mobile device and/or occupant inside of a building isdescribed in greater detail in commonly-assigned U.S. patent applicationSer. No. 14/832,798, filed Aug. 21, 2015, entitled LOAD CONTROL SYSTEMRESPONSIVE TO LOCATION OF AN OCCUPANT AND MOBILE DEVICES, the entiredisclosure of which is hereby incorporated by reference.

The visible light sensor 180 may comprise a camera directed into theroom 102 and may be configured to record images of the room 102. Forexample, the visible light sensor 180 may be mounted to a ceiling of theroom 102 (as shown in FIG. 1), and/or may be mounted to a wall of theroom. The visible light sensor 180 may comprise a fish-eye lens. If thevisible light sensor 180 is mounted to the ceiling, the images recordedby the camera may be top down views of the room 102.

FIGS. 2A-2G show simplified example images of a room 200 that may berecorded by the camera of the visible light sensor. As shown in FIG. 2A,the room 200 may comprise walls 210 having a doorway 212 and windows214. The room 200 may include a desk 220 on which a computer monitor 222and a keyboard 224 may be located. The room 200 may also include a chair226 on which an occupant of the room 200 may typically be positioned touse the computer monitor 222 and the keypad 224. The example images ofthe room 200 shown in FIGS. 2A-2G are provided for informative purposesand may not be identical to actual images captured by the visible lightsensor 180. Since the visible light sensor 180 may have a fish-eye lens,the actual images captured by the camera may warped images and may notbe actual two-dimensional images as shown in FIGS. 2A-2G. In addition,the example image of the room 200 shown in FIGS. 2A-2G show the walls210 having thickness and actual images captured by the visible lightsensor 180 may only show the interior surfaces of the room 102.

The visible light sensor 180 may be configured to process imagesrecorded by the camera and transmit one or more messages (e.g., digitalmessages) to the load control devices in response to the processedimages. The visible light sensor 180 may be configured to sense one ormore environmental characteristics of a space (e.g., the room 102 and/orthe room 200) from the images. For example, the visible light sensor 180may be configured to operate in one or more sensor modes (e.g., anoccupancy and/or vacancy sensor mode, a daylight sensor mode, a colorsensor mode, a glare detection sensor mode, an occupant count mode,etc.) The visible light sensor 180 may execute different algorithms toprocess the images in each of the sensor modes to determine data totransmit to the load control devices. The visible light sensor 180 maytransmit digital messages via the RF signals 108 (e.g., using theproprietary protocol) in response to the images. The visible lightsensor 180 may send the digital messages directly to the load controldevices and/or to the system controller 110 which may then communicatethe messages to the load control devices. The visible light sensor 180may comprise a first communication circuit for transmitting andreceiving the RF signals 108 using the proprietary protocol.

The visible light sensor 180 may be configured to perform a plurality ofsensor events to sense various environmental characteristics of thespace. For example, to perform a sensor event, the visible light sensor180 may be configured to operate in one of sensor modes to execute theappropriate algorithm to sense the environmental characteristic. Inaddition, the visible light sensor 180 may configured to obtain frommemory certain pre-configured operational characteristics (e.g.,sensitivity, baseline values, threshold values, limit values, etc.) thatmay be used by the algorithm to sense the environmental characteristicduring the sensor event. Further, the visible light sensor 180 may beconfigured to focus on one or more regions of interest in the imagerecorded by the camera when processing the image to sense theenvironmental characteristic during the sensor event. For example,certain areas of the image recorded by the camera may be masked (e.g.,digitally masked), such that the visible light sensor 180 may notprocess the portions of the image in the masked areas. The visible lightsensor 180 may be configured to apply a mask (e.g., a predetermineddigital mask that may be stored in memory) to focus on a specific regionof interest, and process the portion of the image in the region ofinterest. In addition, the visible light sensor 180 may be configured tofocus on multiple regions of interest in the image at the same time(e.g., as shown in FIGS. 2B-2G). Specific mask(s) may be defined foreach sensor event.

The visible light sensor 180 may be configured to dynamically changebetween the sensor modes, apply digital masks to the images, and adjustoperational characteristics depending upon the present sensor event. Thevisible light sensor 180 may be configured to perform a number ofdifferent sensor events to sense a plurality of the environmentalcharacteristics of the space. For example, the visible light sensor 180may be configured to sequentially and/or periodically step through thesensor events to sense the plurality of the environmentalcharacteristics of the space. Each sensor events may be characterized bya sensor mode (e.g., specifying an algorithm to use), one or moreoperational characteristics, and one or more digital masks.

The visible light sensor 180 may be configured to operate in theoccupancy and/or vacancy sensor mode to determine an occupancy and/orvacancy condition in the space in response to detection of movementwithin one or more regions of interest. The visible light sensor 180 maybe configured to use an occupancy and/or vacancy detection algorithm todetermine that the space is occupied in response to the amount ofmovement and/or the velocity of movement exceeding an occupancythreshold.

During a sensor event for detecting occupancy and/or vacancy, thevisible light sensor 180 may be configured to apply a predetermined maskto focus on one or more regions of interest in one or more imagesrecorded by the camera and determine occupancy or vacancy of the spacebased on detecting or not detecting motion in the regions of interest.The visible light sensor 180 may be responsive to movement in theregions of interest and not be responsive to movement in the masked-outareas. For example, as shown in FIG. 2B, the visible light sensor 180may be configured to apply a mask 230 to an image of the room 200 toexclude detection of motion in the doorway 212 or the windows 214, andmay focus on a region of interest 232 that include the interior space ofthe room 200. The visible light sensor 180 may be configured to apply afirst mask to focus on a first region of interest, apply a second maskto focus on a second region of interest, and determine occupancy orvacancy based on movement detected in either of the regions of interest.In addition, the visible light sensor 180 may be configured to focus onmultiple regions of interest in the image at the same time by applyingdifferent masks to the image(s).

The visible light sensor 180 may be configured to adjust certainoperational characteristics (e.g., sensitivity) to be used by theoccupancy and/or vacancy algorithm depending upon the present sensorevent. The occupancy threshold may be dependent upon the sensitivity.For example, the visible light sensor 180 may be configured to be moresensitive or less sensitive to movements in a first region of interestthan in a second region of interest. For example, as shown in FIG. 2C,the visible light sensor 180 may be configured to increase thesensitivity and apply a mask 240 to focus on a region of interest 242around the keyboard 224 to be more sensitive to movements around thekeyboard. In other words, by using masks that focus on “smaller” vs“larger” (e.g., the keyboard vs. the desk surface on which the keyboardmay sit), the visible light sensor 180 may be configured to increaseand/or decrease the sensitivity of detected or not detected movements.In addition, through the use of masks, visible light sensor 180 may beconfigured to not simply detect movement in the space, but detect wherethat movement occurred.

The visible light sensor 180 may also be configured to determine anoccupancy and/or vacancy condition in the space in response to anoccupant moving into or out of a bounded area. For example, as shown inFIG. 2D, the visible light sensor 180 may be configured to determine anoccupancy condition in the room 200 in response to the occupant crossinga boundary of a bounded area 250 surrounding the chair 226 to enter thebounded area. After the occupant crosses the boundary, the visible lightsensor 180 may assume that the space is occupied (e.g., independent ofother sensor events of occupancy and/or vacancy) until the occupantleaves the bounded area 250. The visible light sensor 180 may not beconfigured to determine a vacancy condition in the room 200 until theoccupancy crosses the boundary of the bounded area 250 to exit thebounded area. After the occupant leaves the bounded area, the visiblelight sensor 180 may be configured to detect a vacancy condition, forexample, in response to determining that there is no movement in theregion of interest 232 as shown in FIG. 2B. Thus, the visible lightsensor 180 can maintain the occupancy condition even if the movement ofthe occupant are fine movements (e.g., if the occupant is sitting stillor reading in the chair 226) or no movements (e.g., if the occupant issleeping in a bed).

The bounded area may surround other structures in different types ofrooms (e.g., other than the room 200 shown in FIG. 2D). For example, ifthe bounded area surrounds a hospital bed in a room, the systemcontroller 110 may be configured to transmit an alert to the hospitalstaff in response to the detection of movement out of the region ofinterest (e.g., indicating that the patient got up out of the bed). Inaddition, the visible light sensor 180 may be configured count thenumber of occupants entering and exiting a bounded area.

The visible light sensor 180 may transmit digital messages to the systemcontroller 110 via the RF signals 108 (e.g., using the proprietaryprotocol) in response to detecting the occupancy or vacancy conditions.The system controller 110 may be configured to turn the lighting loads(e.g., lighting load 122 and/or the LED light source 132) on and off inresponse to receiving an occupied command and a vacant command,respectively. Alternatively, the visible light sensor 180 may transmitdigital messages directly to the lighting loads. The visible lightsensor 180 may operate as a vacancy sensor, such that the lighting loadsare only turned off in response to detecting a vacancy condition (e.g.,and not turned on in response to detecting an occupancy condition).Examples of RF load control systems having occupancy and vacancy sensorsare described in greater detail in commonly-assigned U.S. Pat. No.8,009,042, issued Aug. 30, 2011 Sep. 3, 2008, entitled RADIO-FREQUENCYLIGHTING CONTROL SYSTEM WITH OCCUPANCY SENSING; U.S. Pat. No. 8,199,010,issued Jun. 12, 2012, entitled METHOD AND APPARATUS FOR CONFIGURING AWIRELESS SENSOR; and U.S. Pat. No. 8,228,184, issued Jul. 24, 2012,entitled BATTERY-POWERED OCCUPANCY SENSOR, the entire disclosures ofwhich are hereby incorporated by reference.

The visible light sensor 180 may also be configured to operate in thedaylight sensor mode to measure a light intensity at a location of thespace. For example, the visible light sensor 180 may apply a digitalmask to focus on only a specific location in the space (e.g., on a tasksurface, such as a table 106 as shown in FIG. 1) and may use adaylighting algorithm to measure the light intensity at the location.For example, as shown in FIG. 2E, the visible light sensor 180 may beconfigured to apply a mask 260 to focus on a region of interest 262 thatincludes the surface of the desk 220. The visible light sensor 180 maybe configured to integrate light intensities values of the pixels of theimage across the region of interest 262 to determine a measured lightintensity at the surface of the desk.

The visible light sensor 180 may transmit digital messages (e.g.,including the measured light intensity) to the system controller 110 viathe RF signals 108 for controlling the intensities of the lighting load122 and/or the LED light source 132 in response to the measured lightintensity. The visible light sensor 180 may be configured to focus onmultiple regions of interest in the image recorded by the camera andmeasure the light intensity in each of the different regions ofinterest. Alternatively, the visible light sensor 180 may transmitdigital messages directly to the lighting loads. The visible lightsensor 180 may be configured to adjust certain operationalcharacteristics (e.g., gain) based on the region of interest in whichthe light intensity is presently being measured. Examples of RF loadcontrol systems having daylight sensors are described in greater detailin commonly-assigned U.S. Pat. No. 8,410,706, issued Apr. 2, 2013,entitled METHOD OF CALIBRATING A DAYLIGHT SENSOR; and U.S. Pat. No.8,451,116, issued May 28, 2013, entitled WIRELESS BATTERY-POWEREDDAYLIGHT SENSOR, the entire disclosures of which are hereby incorporatedby reference.

The system controller 110 may be configured to determine a degradationin the light output of one or more of the lighting loads (e.g., thelighting load 122 and/or the LED light source 132) in the space, and tocontrol the intensities of the lighting loads to compensate for thedegradation (e.g., lumen maintenance). For example, the systemcontroller 110 may be configured to individually turn on each lightingload (e.g., when it is dark at night) and measure the magnitude of thelight intensity at a location (e.g., on the table 106 or the desk 220).For example, the system controller 110 may be configured to turn on thelighting load 122 at night and control the visible light sensor 180 torecord an image of the room, to apply a mask to focus on a region ofinterest that the lighting load 122 illuminates (e.g., the surface oftable 106 or the desk 220), to measure the light intensity in thatregion of interest, and to communicate that value to the systemcontroller 110. The system controller 110 may store this value as abaseline value. At a time and/or date thereafter, the system controller110 may repeat the measurement and compare the measurement to thebaseline value. If the system controller 110 determines there to be adegradation, it may control the lighting load 122 to compensate for thedegradation, alert maintenance, etc.

The visible light sensor 180 may also be configured to operate in thecolor sensor mode to sense a color (e.g., measure a color temperature)of the light emitted by one or more of the lighting loads in the space(e.g., to operate as a color sensor and/or a color temperature sensor).For example, as shown in FIG. 2F, the visible light sensor 180 may beconfigured to apply a mask 270 to focus on a region of interest 272(that includes a portion of the surface of the desk 220) and may use acolor sensing algorithm to determine a measured color and/or colortemperature in the room 200. For example, the visible light sensor 180may integrate color values of the pixels of the image across the regionof interest 272 to determine the measured color and/or color temperaturein the room 200. The visible light sensor 180 may transmit digitalmessages (e.g., including the measured color temperature) to the systemcontroller 110 via the RF signals 108 for controlling the color (e.g.,the color temperatures) of the lighting load 122 and/or the LED lightsource 132 in response to the measured light intensity (e.g., colortuning of the light in the space). Alternatively, the visible lightsensor 180 may transmit digital messages directly to the lighting loads.An example of a load control system for controlling the colortemperatures of one or more lighting loads is described in greaterdetail in commonly-assigned U.S. Patent Application Publication No.2014/0312777, published Oct. 23, 2014, entitled SYSTEMS AND METHODS FORCONTROLLING COLOR TEMPERATURE, the entire disclosure of which is herebyincorporated by reference.

The visible light sensor 180 may be configured to operate in a glaredetection sensor mode. For example, the visible light sensor 180 may beconfigured execute a glare detection algorithm to determine a depth ofdirect sunlight penetration into the space from the image recorded bythe camera. For example, as shown in FIG. 2G, the visible light sensor180 may be configured to apply a mask 280 to focus on a region ofinterest 282 on the floor of the room 200 near the windows 214 to sensethe depth of direct sunlight penetration into the room. Based on adetection and/or measurement of the depth of direct sunlight penetrationinto the room, the visible light sensor 180 may transmit digitalmessages to the system controller 110 via the RF signals 108 to limitthe depth of direct sunlight penetration into the space, for example, toprevent direct sunlight from shining on a surface (e.g., the table 106or the desk 220). The system controller 110 may be configured to lowerthe window treatment fabric 152 of each of the motorized windowtreatments 150 to prevent the depth of direct sunlight penetration fromexceeded a maximum sunlight penetration depth. Alternatively, thevisible light sensor 180 may be configured to directly control thewindow treatments 150 to lower of the window treatment fabric 152.Examples of methods for limiting the sunlight penetration depth in aspace are described in greater detail in commonly-assigned U.S. Pat. No.8,288,981, issued Oct. 16, 2012, entitled METHOD OF AUTOMATICALLYCONTROLLING A MOTORIZED WINDOW TREATMENT WHILE MINIMIZING OCCUPANTDISTRACTIONS, the entire disclosure of which is hereby incorporated byreference.

The visible light sensor 180 may be configured to focus only on daylightentering the space through, for example, one or both of the windows 104(e.g., to operate as a window sensor). The system controller 110 may beconfigured to control the lighting loads (e.g., the lighting load 122and/or the LED light source 132) in response to the magnitude of thedaylight entering the space. The system controller 110 may be configuredto override automatic control of the motorized window treatments 150,for example, in response to determining that it is a cloudy day or anextremely sunny day. Alternatively, the visible light sensor 180 may beconfigured to directly control the window treatments 150 to lower of thewindow treatment fabric 152. Examples of load control systems havingwindow sensors are described in greater detail in commonly-assigned U.S.Patent Application Publication No. 2014/0156079, published Jun. 5, 2014,entitled METHOD OF CONTROLLING A MOTORIZED WINDOW TREATMENT, the entiredisclosure of which is hereby incorporated by reference.

The visible light sensor 180 may be configured to detect a glare source(e.g., sunlight reflecting off of a surface) outside or inside the spacein response to the image recorded by the camera. The system controller110 may be configured to lower the window treatment fabric 152 of eachof the motorized window treatments 150 to eliminate the glare source.Alternatively, the visible light sensor 180 may be configured todirectly control the window treatments 150 to lower of the windowtreatment fabric 152 to eliminate the glare source.

The visible light sensor 180 may also be configured to operate in theoccupant count mode and may execute an occupant count algorithm to countthe number of occupants a particular region of interest, and/or thenumber of occupants entering and/or exiting the region of interest. Forexample, the system controller 110 may be configured to control the HVACsystem 162 in response to the number of occupants in the space. Thesystem controller 110 may be configured to control one or more of theload control devices of the load control system 100 in response to thenumber of occupants in the space exceeding an occupancy numberthreshold. Alternatively, the visible light sensor 180 may be configuredto directly control the HVAC system 162 and other load control devices.

The operation of the load control system 100 may be programmed andconfigured using, for example, the mobile device 190 or other networkdevice (e.g., when the mobile device is a personal computing device).The mobile device 190 may execute a graphical user interface (GUI)configuration software for allowing a user to program how the loadcontrol system 100 will operate. For example, the configuration softwaremay run as a PC application or a web interface. The configurationsoftware and/or the system controller 110 (e.g., via instructions fromthe configuration software) may generate a load control database thatdefines the operation of the load control system 100. For example, theload control database may include information regarding the operationalsettings of different load control devices of the load control system(e.g., the dimmer switch 120, the LED driver 130, the plug-in loadcontrol device 140, the motorized window treatments 150, and/or thethermostat 160). The load control database may comprise informationregarding associations between the load control devices and the inputdevices (e.g., the remote control device 170, the visible light sensor180, etc.). The load control database may comprise information regardinghow the load control devices respond to inputs received from the inputdevices. Examples of configuration procedures for load control systemsare described in greater detail in commonly-assigned U.S. Pat. No.7,391,297, issued Jun. 24, 2008, entitled HANDHELD PROGRAMMER FOR ALIGHTING CONTROL SYSTEM; U.S. Patent Application Publication No.2008/0092075, published Apr. 17, 2008, entitled METHOD OF BUILDING ADATABASE OF A LIGHTING CONTROL SYSTEM; and U.S. patent application Ser.No. 13/830,237, filed Mar. 14, 2013, entitled COMMISSIONING LOAD CONTROLSYSTEMS, the entire disclosure of which is hereby incorporated byreference.

The operation of the visible light sensor 180 may be programmed andconfigured using the mobile device 190 or other network device. Thevisible light sensor 180 may comprise a second communication circuit fortransmitting and receiving the RF signals 109 (e.g., directly with thenetwork device 190 using a standard protocol, such as Wi-Fi orBluetooth). During the configuration procedure of the load controlsystem 100, the visible light sensor 180 may be configured to record animage of the space and transmit the image to the network device 190(e.g., directly to the network device via the RF signals 109 using thestandard protocol). The network device 190 may display the image on thevisual display and a user may configure the operation of the visiblelight sensor 180 to set one or more configuration parameters (e.g.,configuration information) of the visible light sensor. For example, fordifferent environmental characteristic to be sensed and controlled bythe visible light sensor 180 (e.g., occupant movements, light levelinside of the room, daylight level outside of the room), the user mayindicate different regions of interest on the image by tracing (such aswith a finger or stylus) masked areas on the image displayed on thevisual display. The visible light sensor 180 may be configured toestablish different masks and/or operational characteristics dependingupon the environmental characteristic to be sensed (e.g., occupantmovements, light level inside of the room, daylight level outside of theroom, color temperature, etc.).

After configuration of the visible light sensor 180 is completed at thenetwork device 190, the network device may transmit configurationinformation to the visible light sensor (e.g., directly to the visiblelight sensor via the RF signals 109 using the standard protocol). Thevisible light sensor 180 may store the configuration information inmemory, such that the visible light sensor may operate appropriatelyduring normal operation. For example, for each sensor event the visiblelight sensor 180 is to monitor, the network device 190 may transmit tothe visible light sensor 180 the sensor mode for the event, one or moremasks defining regions of interest for the event, possibly an indicationof the algorithm to be used to sense the environmental characteristic ofthe event, and one or more operational characteristics for the event.

The visible light sensor 180 may be configured in a way that protectsthe privacy of the occupants of the space. For example, the visiblelight sensor 180 may not be configured to transmit images during normaloperation. The visible light sensor 180 may be configured to only usethe images internally to sense the desired environmental characteristic(e.g., to detect occupancy or vacancy, to measure an ambient lightlevel, etc.). For example, the visible light sensor 180 may beconfigured to transmit (e.g., only transmit) an indication of thedetected state and/or measured environmental characteristic duringnormal operation (e.g., via the RF signals 108 using the proprietaryprotocol).

The visible light sensor 180 may be installed with special configurationsoftware for use during the configuration procedure (e.g., for use onlyduring the configuration procedure). The configuration software mayallow the visible light sensor 180 to transmit a digital representationof an image recorded by the camera to the network device 190 only duringthe configuration procedure. The visible light sensor 180 may receiveconfiguration information from the network device 190 (e.g., via the RFsignals 109 using the standard protocol) and may store the configurationinformation in memory. The visible light sensor 180 may have theconfiguration software installed during manufacturing, such that thevisible light sensor 180 is ready to be configured when first poweredafter installation. In addition, the system controller 110 and/or thenetwork device 190 may be configured to transmit the configurationsoftware to the visible light sensor 180 during the configurationprocedure of the load control system 100.

The visible light sensor 180 may be configured to install normaloperation software in place of the configuration software after theconfiguration procedure is complete. The normal operation software maynot allow the visible light sensor 180 to transmit images recorded bythe camera to other devices. The visible light sensor 180 may have thenormal operation software stored in memory and may be configured toinstall the normal operation software after the configuration procedureis complete. In addition, the system controller 110 and/or the networkdevice 190 may be configured to transmit the normal operation softwareto the visible light sensor 180 after the configuration procedure iscomplete.

Rather than installing special configuration software onto the visiblelight sensor 180 and then removing the special configuration softwarefrom the visible light sensor, a special configuration sensor (notshown) may be installed at the location of the visible light sensor 180(e.g., in place of the visible light sensor 180) during configuration ofthe load control system 100. The configuration sensor may include thesame camera and mechanical structure as the visible light sensor 180.The configuration sensor may include a first communication circuit fortransmitting and receiving the RF signals 108 using the proprietaryprotocol and a second communication circuit for transmitting andreceiving the RF signals 109 using the standard protocol. During theconfiguration procedure of the load control system 100, theconfiguration sensor may be configured to record an image of the spaceand transmit the image to the network device 190 (e.g., directly to thenetwork device via the RF signals 109 using the standard protocol). Thenetwork device 190 may display the image on the visual display and auser may configure the operation of the visible light sensor 180. Forexample, the visible light sensor 180 and the configuration sensor maybe mounted to a base portion that remains connected to the ceiling orwall, such that the configuration sensor may be mounted in the exactsame location during configuration that the visible light sensor ismounted during normal operation.

The configuration sensor may then be uninstalled and the visible lightsensor 180 may be installed in its place for use during normal operationof the load control system 100. The visible light sensor 180 for useduring normal operation may not be capable of transmitting images viathe RF signals 109 using the standard protocol. The visible light sensor180 for use during normal operation may only comprise a communicationcircuit for transmitting and receiving the RF signals 108 using theproprietary protocol. After the visible light sensor 180 is installed,the network device 190 may transmit the configuration information to thesystem controller 110 via the RF signals 109 (e.g., using the standardprotocol), and the system controller may transmit the configurationinformation to the visible light sensor via the RF signal 108 (e.g.,using the proprietary protocol). The visible light sensor 180 may storethe configuration information in memory of the sensor. During normaloperation, the visible light sensor 180 may transmit, for example, anindication of the sensed environmental characteristic during normaloperation via the RF signals 108 (e.g., using the proprietary protocol).

Further, the visible light sensor 180 may comprise a removableconfiguration module for use during configuration of the visible lightsensor 180. The visible light sensor 180 may comprise a firstpermanently-installed communication circuit for transmitting andreceiving the RF signals 108 using the proprietary protocol. Theremovable configuration module may comprise a second communicationcircuit for transmitting and receiving the RF signals 109 using thestandard protocol. When the configuration module is installed in thevisible light sensor 180 and the second communication circuit iselectrically coupled to the visible light sensor, the visible lightsensor may record an image of the space and transmit the image to thenetwork device 190 (e.g., directly to the network device via the RFsignals 109 using the standard protocol). The network device 190 maytransmit the configuration information to the visible light sensor 180while the configuration module is still installed in the visible lightsensor, and the visible light sensor may store the configurationinformation in memory. The configuration module may then be removed fromthe visible light sensor 180, such that the visible light sensor issubsequently unable to transmit images via the RF signals 109 using thestandard protocol.

FIG. 3 is a simplified block diagram of an example visible light sensor300, which may be deployed as the visible light sensor 180 of the loadcontrol system 100 shown in FIG. 1. The visible light sensor 300 maycomprise a control circuit 310, for example, a microprocessor, aprogrammable logic device (PLD), a microcontroller, an applicationspecific integrated circuit (ASIC), a field-programmable gate array(FPGA), or any suitable processing device. The control circuit 310 maybe coupled to a memory 312 for storage of sensor events, masks,operational characteristics, etc. of the visible light sensor 300. Thememory 312 may be implemented as an external integrated circuit (IC) oras an internal circuit of the control circuit 310.

The visible light sensor 300 may comprise a visible light sensingcircuit 320 having an image recording circuit, such as a camera 322, andan image processing circuit, such as a processor 324. The imageprocessor 324 may comprise a digital signal processor (DSP), amicroprocessor, a programmable logic device (PLD), a microcontroller, anapplication specific integrated circuit (ASIC), a field-programmablegate array (FPGA), or any suitable processing device. The camera 322 maybe positioned towards a space in which one or more environmentalcharacteristics are to be sensed in a space (e.g., into the room 102 orthe room 200). The camera 322 may be configured to capture or record animage. For example, the camera 3222 may be configured to capture imagesat a particular sampling rate, where a single image may be referred toas a frame acquisition. One example frame acquisition rate isapproximately ten frames per second. The frame acquisition rate may belimited to reduce the required processing power of the visible lightsensor. Each image may consist of an array of pixels, where each pixelhas one or more values associated with it. A raw RGB image may havethree values for each pixel: one value for each of the red, green, andblue intensities, respectively. One implementation may use the existingRGB system for pixel colors, where each component of the intensity has avalue from 0-255. For example, a red pixel would have an RGB value of(255, 0, 0), whereas a blue pixel would have an RGB value of (0, 0,255). Any given pixel that is detected to be a combination of red,green, and/or blue may be some combination of (0-255, 0-255, 0-255). Onewill recognize that over representations for an image may be used.

The camera 322 may provide the captured image (e.g., a raw image) to theimage processor 324. The image processor 324 may be configured toprocess the image and provide to the control circuit 310 one or moresense signals that are representative of the sensed environmentalcharacteristics (e.g., an occurrence of movement, an amount of movement,a direction of movement, a velocity of movement, a counted number ofoccupants, a light intensity, a light color, an amount of directsunlight penetration, etc.). For example, the one or more sense signalsprovided to the control circuit 310 may be representative of movement inthe space and/or a measured light level in the space.

In addition, the image processor 324 may provide a raw image or aprocessed (e.g., preprocessed) image to the control circuit 310, whichmay be configured to process the image to determine sensed environmentalcharacteristics. Regardless, the control circuit 310 may then use thesensed environmental characteristics to transmit control commands toload devices (e.g., directly or through system controller 110).

One example of a processed image, as is known in the art, is theluminance of a pixel, which can be measured from the image RGB by addingR, G, B intensity values, weighted according to the following formula:

Luminance (perceived)=(0.299*R+0.587*G+0.114*B).

The example weighting coefficients factor in the non-uniform response ofthe human eye to different wavelengths of light. However, othercoefficients may alternatively be used.

As previously mentioned, if the visible light sensor 300 have a fish-eyelens, the image captured by the camera 322 may be warped. The imageprocessor 324 may be configured to preprocess the image to warp theimage and to generate a non-warped image (e.g., as shown in FIGS.2A-2G).

Another image processing technique includes mapping the RGB sensorresponse to CIE tristimulus values to acquire chromaticity coordinatesand thereby the Correlated Color Temperature (CCT). An example method isdescribed by Joe Smith in the following reference: Calculating ColorTemperature and Illuminance using the TAOS TCS3414CS Digital ColorSensor, Intelligent Opto Sensor Designer's Notebook, Feb. 27, 2009.Another known example of a processed image is an image to which adigital filter, or a digital mask has been applied. A digital mask maybe used to eliminate regions within the image which have little to novalue for further analysis and processing. Alternatively, a complementof a digital mask is a region of interest, or an area within an imagethat has been identified for further processing or analysis. A processedimage may also be created via a technique known as backgroundsubtraction. Using this technique, a background image, whichincorporates the history of the image over time (here, the previousstate of the room), may be subtracted from the current image (currentstate of the room) in order to identify differences in the images.Background subtraction is useful for detecting movement in an image andfor occupancy and vacancy detection. Various algorithms may be used forbackground maintenance, to determine how to effectively combine pixelsover time into the background image. Some example background maintenancealgorithms include: adjusted frame difference, mean and threshold, meanand covariance, mixture of Gaussians, and normalized block correlation.These and other similar details inherent to image processing would befamiliar to one skilled in the art.

The control circuit 310 and/or the image processor 324 may be configuredto apply one or more masks to focus on one or more regions of interestin the image (e.g., the raw image and/or the preprocessed image) tosense one or more environmental characteristics of the space. As usedherein, a mask may be any definition to define a region of interest ofan image. For example, assuming an image may be defined as an N×M arrayof pixels where each pixel has a defined coordinate/position in thearray, a mask be defined as a sequence of pixel coordinates that definethe outer perimeter of a region of interest within the image. As anotherexample, a mask may be define as an N×M array that corresponds to theN×M array of pixels of an image. Each entry of the mask be a 1 or 0, forexample, whereby entries having a 1 define the region of interest. Sucha representation may allow and image array and a mask array to be“ANDED” to cancel or zero out all pixels of the image that are not ofinterest. As another alternative, rather than a mask defining the regionof interest of the image, it may define the region that in not ofinterest. These are merely examples and other representations may beused.

The visible light sensor 300 may comprise a first communication circuit330 configured to transmit and receive digital messages via a firstcommunication link using a first protocol. For example, the firstcommunication link may comprise a wireless communication link and thefirst communication circuit 330 may comprise an RF transceiver coupledto an antenna. In addition, the first communication link may comprise awired digital communication link and the first communication circuit 330may comprise a wired communication circuit. The first protocol maycomprise a proprietary protocol, such as, for example, the ClearConnectprotocol. The control circuit 310 may be configured to transmit andreceive digital messages via the first communication link during normaloperation of the visible light sensor 300. The control circuit 310 maybe configured to transmit an indication of the sensed environmentalcharacteristic via the first communication link during normal operationof the visible light sensor 300. For example, the control circuit 310may be configured to transmit an indication of a detected state (e.g.,an occupancy or vacancy condition) and/or a measured environmentalcharacteristic (e.g., a measured light level) via the firstcommunication link during normal operation of the visible light sensor300.

The visible light sensor 300 may comprise a second communication circuit332 configured to transmit and receive digital messages via a secondcommunication link using a second protocol. For example, the secondcommunication link may comprise a wireless communication link and thesecond communication circuit 332 may comprise an RF transceiver coupledto an antenna. In addition, the second communication link may comprise awired digital communication link and the second communication circuit332 may comprise a wired communication circuit. The second protocol maycomprise a standard protocol, such as, for example, the Wi-Fi protocol,the Bluetooth protocol, the Zigbee protocol, etc. The control circuit310 may be configured to transmit and receive digital messages via thesecond communication link during configuration of the visible lightsensor 300. For example, the control circuit 310 may be configured totransmit an image recorded by the camera 322 via the secondcommunication link during configuration of the visible light sensor 300.

The visible light sensor 300 may comprise a power source 340 forproducing a DC supply voltage V_(CC) for powering the control circuit310, the memory 312, the image processor 324, the first and secondcommunication circuits 330, 332, and other low-voltage circuitry of thevisible light sensor 300. The power source 340 may comprise a powersupply configured to receive an external supply voltage from an externalpower source (e.g., an AC mains line voltage power source and/or anexternal DC power supply). In addition, the power source 340 maycomprise a battery for powering the circuitry of the visible lightsensor 300.

The visible light sensor 300 may further comprise a low-power occupancysensing circuit, such as a passive infrared (PIR) detector circuit 350.The PIR detector circuit 350 may generate a PIR detect signal V_(PIR)(e.g., a low-power occupancy signal) that is representative of anoccupancy and/or vacancy condition in the space in response to detectedpassive infrared energy in the space. The PIR detector circuit 350 mayconsume less power than the visible light sensing circuit 320. However,the visible light sensing circuit 320 may be more accurate than the PIRdetector circuit 350. For example, when the power source 340 is abattery, the control circuit 310 may be configured to disable thevisible light sensing circuit 320 and use the PIR detector circuit 350to detect occupancy conditions. The control circuit 310 may disable thelight sensing circuit 320, for example, when the space is vacant. Thecontrol circuit 310 may detect an occupancy condition in the space inresponse to the PIR detect signal V_(PIR) and may subsequently enablethe visible light sensing circuit 320 to detect a continued occupancycondition and/or a vacancy condition. The control circuit 310 may enablethe visible light sensing circuit 320 immediately after detecting anoccupancy condition in the space in response to the PIR detect signalV_(PIR). The control circuit 310 may also keep the visible light sensingcircuit 320 disabled after detecting an occupancy condition in the space(in response to the PIR detect signal V_(PIR)). The control circuit 310may keep the visible light sensing circuit 320 disabled until the PIRdetect signal V_(PIR) indicates that the space is vacant. The controlcircuit 310 may not make a determination that the space is vacant untilthe visible light sensing circuit 320 subsequently indicates that thespace is vacant.

The visible light sensor 300 may be configured in a way that protectsthe privacy of the occupants of the space. For example, the controlcircuit 310 may execute special configuration software that allows thecontrol circuit 310 to transmit an image recorded by the camera 322 viathe second communication link only during configuration of the visiblelight sensor 300. The configuration software may be installed in thememory 312 during manufacturing, such that the visible light sensor 300is ready to be configured when first powered after installation. Inaddition, the control circuit 310 may be configured to receive theconfiguration software via the first or second communication links andstore the configuration software in the memory during configuration ofthe visible light sensor 300. The control circuit 310 may execute normaloperation software after configuration of the visible light sensor 300is complete. The normal operation software may be installed in thememory 312 or may be received via the first or second communicationlinks during configuration of the visible light sensor 300.

The second communication circuit 332 may be housed in a removableconfiguration module that may be installed in the visible light sensor320 and electrically connected to the control circuit 310 only duringconfiguration of the visible light sensor. When the configuration moduleis installed in the visible light sensor 300 and the secondcommunication circuit 332 is electrically coupled to the control circuit310 (e.g., via a connector 334), the control circuit may transmit animage recorded by the camera 322 to via the second communication link.The control circuit 310 may subsequently receive configurationinformation via the first or second communication links and may storethe configuration information in the memory 312. The configurationmodule may then be removed from the visible light sensor 300, such thatthe control circuit 310 is subsequently unable to transmit images viathe second communication link.

In addition, the visible light sensor 300 that is installed in the spaceduring normal operation may not comprise the second communicationcircuit, such that the visible light sensor is never able to transmitimages via the second communication link. The visible light sensor 300may be configured using a special configuration sensor that may have anidentical structure as the visible light sensor 300 shown in FIG. 3 andmay include both a first communication circuit for communicating via thefirst communication link and a second communication circuit forcommunicating via the second communication link. The specialconfiguration sensor may be configured to record an image using thecamera and transmit the image via the second communication link. Thespecial configuration sensor may then be uninstalled and the visiblelight sensor 300 (that does not have the second communication link 332)may then be installed in its place for use during normal operation. Thecontrol circuit 310 of the visible light sensor 300 may receiveconfiguration information via the first communication link and may storethe configuration information in the memory 312.

FIG. 4 shows a flowchart of an example control procedure 400 executedperiodically by a control circuit of a visible light sensor (e.g., thecontrol circuit 310 of the visible light sensor 300) at step 410. In thecontrol procedure 400, the control circuit may operate in an occupiedstate when an occupancy condition is detected and in a vacant state whena vacancy condition is detected. If the control circuit is not operatingin the occupied state at step 412, the control circuit may sample alow-power occupancy signal (e.g., the PIR detect signal V_(PIR)) at step414. If the PIR detect signal V_(PIR) indicates that the space is vacantat step 416, the control procedure 400 may simply exit. If the PIRdetect signal V_(PIR) indicates that the space is occupied at step 416,the control circuit may change to the occupied state at step 418,transmit an occupied message (e.g., via the first communication linkusing the proprietary protocol) at step 420, and enable a visible lightsensing circuit (e.g., the visible light sensing circuit 320) at step422, before the control procedure 400 exits. As shown in FIG. 4, thecontrol circuit may enable the visible light sensing circuit immediatelyafter detecting an occupancy condition in response to the PIR detectsignal V_(PIR).

If the control circuit is operating in the occupied state at step 412,the control circuit may monitor the visible light sensing circuit (e.g.,monitor the sense signals generated by visible light sensing circuit) atstep 424. If the visible light sensing circuit indicates that the spaceis vacant at step 426, the control circuit may start a vacancy timer atstep 428, before the control procedure 400 exits. If the vacancy timerexpires without the control circuit detecting any further movement inthe space, the control circuit may then switch to the vacant state. Ifthe visible light sensing circuit indicates that the space is occupiedat step 426, the control circuit may reset and stop the vacancy timer atstep 430, before the control procedure 400 exits.

FIG. 5 shows a flowchart of another example control procedure 500executed periodically by a control circuit of a visible light sensor(e.g., the control circuit 310 of the visible light sensor 300) at step510. If the control circuit is not operating in the occupied state atstep 512, the control circuit may sample a low-power occupancy signal(e.g., the PIR detect signal V_(PIR)) at step 514. If the PIR detectsignal V_(PIR) indicates that the space is vacant at step 516, thecontrol procedure 500 may simply exit. If the PIR detect signal V_(PIR)indicates that the space is occupied at step 516, the control circuitmay change to the occupied state at step 518 and transmit an occupiedmessage (e.g., via the first communication link using the proprietaryprotocol) at step 520, before the control procedure 500 exits.

If the control circuit is operating in the occupied state at step 512and a visible light sensing circuit (e.g., the visible light sensingcircuit 220) is presently disabled at step 522, the control circuit maysample the PIR detect signal V_(PIR) at step 524. If the PIR detectsignal V_(PIR) indicates that the space is occupied at step 526, thecontrol procedure 500 may simply exit. If the PIR detect signal V_(PIR)indicates that the space is vacant at step 516, the control circuit mayenable the visible light sensing circuit at step 528 and monitor thevisible light sensing circuit (e.g., monitor the sense signals generatedby visible light sensing circuit) at step 530. As shown in FIG. 5, thecontrol circuit may keep the visible light sensing circuit disableduntil the PIR detect signal V_(PIR) indicates that the space is vacant.

If the visible light sensing circuit is already enabled at step 522, thecontrol circuit may simply monitor the visible light sensing circuit atstep 530. If the visible light sensing circuit indicates that the spaceis vacant at step 532, the control circuit may start a vacancy timer atstep 534, before the control procedure 500 exits. If the visible lightsensing circuit indicates that the space is occupied at step 532, thecontrol circuit may reset and stop the vacancy timer at step 536, beforethe control procedure 500 exits.

FIG. 6 is a flowchart of an example vacancy timer procedure 600 executedby a control circuit of a visible light sensor (e.g., the controlcircuit 310 of the visible light sensor 300) when the vacancy timerexpires at step 610. The control circuit may first change to the vacantstate at step 612 and transmit a vacant message (e.g., via the firstcommunication link using the proprietary protocol) at step 614. Thecontrol circuit may then disable the visible light sensing circuit atstep 616, before the vacancy timer procedure 600 exits.

FIG. 7 shows a flowchart of an example sensor event procedure 700 thatmay be executed by a control circuit of a visible light sensor (e.g.,the control circuit 310 of the visible light sensor 300). The controlcircuit may execute the sensor event procedure 700 to step throughsensor events to sense a plurality of environmental characteristics of aspace (e.g., the room 102 or the room 200). For example, the sensorevent procedure 700 may begin at step 710 during normal operation of thevisible light sensor. At step 712, the control circuit may determine thenext sensor event that may be stored in memory. For example, the firsttime that the control circuit executes step 712, the control circuit mayretrieve the first sensor event from memory. The control circuit maythen retrieves an image from a camera and/or an image processor of thevisible light sensor (e.g., the camera 322 and/or the image processor324) at step 714. For example, the control circuit may retrieve a rawimage (e.g., a frame acquisition from the camera 322) or a preprocessedimage (e.g., a background-subtracted image).

At step 716, the control circuit may determine an algorithm to use toprocess the image to sense the environmental characteristic of thepresent sensor event. At step 718, the control circuit may determineoperational characteristics to use when executing the algorithm for thepresent sensor event. At step 720, the control circuit may apply amask(s) (e.g., that may be stored in memory for the present sensorevent) to the image (e.g., that may be retrieved at step 714) in orderto focus on one or more regions of interest in the image. The controlcircuit may then process the region of interest of the image using thedetermined algorithm and operational characteristics of the presentsensor event at step 722 and transmit the result (e.g., via RF signals108 using the first communication circuit 330) at step 724. If thecontrol circuit should continue normal operation at step 726, the sensorevent procedure 700 may loop around to execute the next sensor event atsteps 712-724. If the control circuit should cease normal operation atstep 726 (e.g., in response to a user input to cease normal operation orother interrupt to normal operation), the sensor event procedure 700 mayexit.

A designer or specifier of the space may set target illuminance levelsfor the amount of light shining directly on a task surface (e.g., thetable 106 or the desk 220). The load control system may be commissionedto operate within the target illuminance levels. To calibrate thevisible light sensor to the light levels within the space, a luminancemeasurement may be taken with the lights at a high-end (or full)intensity when no external light is present (e.g., at nighttime or withcovering material of all motorized window treatments in the space fullyclosed). The luminance measurement may be taken for the entire image, ormay be integrated over a region of interest. The luminance measurementtaken with no external light may be used as a baseline for comparisonwith subsequent luminance measurements. For example, the visible lightsensor may periodically record a new baseline (nightly, monthly,bimonthly, etc.) and compare the new baseline to the first baseline. Ifthe luminance values have changed significantly (delta between theimages is greater than a depreciation threshold), the visible lightsensor (or a system controller) may determine that the light intensityhas depreciated due to aging of the fixture and may send a command tocompensate for the delta until the new baseline image matches the firstbaseline image (e.g., until the delta is less than the depreciationthreshold).

The visible light sensor may additionally or alternatively measure abaseline and a depreciation delta specific to the color of the lightfixture (e.g., separately for warm white and cool white light emitters).For example, a first baseline color reading may be taken at night withthe covering material of the motorized window treatments closed, and thelighting fixtures set to a high-end (or full) intensity of cool light(e.g., the blue end of the white color spectrum), and a second baselinecolor reading for warm light (e.g., the red end of the white colorspectrum). The baselines may be taken periodically (e.g., nightly ormonthly) to determine if the lumen output of the fixtures hasdepreciated over time. If the visible light sensor determines the lumenoutput has depreciated, the visible light sensor and/or the systemcontroller may instruct the light fixtures to increase the light outputto compensate accordingly.

The baseline images may also be used to determine the amount of externallight in a space. For example, the visible light sensor may record animage and compare it to a stored baseline image. The visible lightsensor may scale or weight the luminance values for the recorded imageor for the baseline based on the current intensity of the light in theroom. For example, if the light fixtures are set to 50%, the visiblelight sensor may scale this intensity to match the baseline, if thebaseline was recorded at a high end intensity of 85%. Once the luminancevalues of the artificial light have been scaled, based on thiscomparison, the visible light sensor may determine the amount ofexternal light present in one or more regions of interest. If thevisible light sensor determines that external light is present, thevisible light sensor and/or the system controller may send a command tothe light fixtures to decrease the light output to meet the targetilluminance for the space. This feedback loop which saves energy byharvesting external light is called daylighting.

The baseline image may further be used in glare detection andmitigation. Furthermore, the luminance of the baseline image may bedetermined in one or more regions of interest within a room. Forexample, the visible light sensor may retrieve an image of the room, mayobtain the region of interest from the image by applying a mask to theimage, and determine a luminance value for the region of interest bycomputing a luminance value for each image pixel making up the region ofinterest and then integrating or averaging the computed luminance valuesto obtain a baseline luminance value.

FIG. 8 is a flowchart of an example glare detection procedure 800, whichmay be executed by a control circuit of a visible light sensor (e.g.,the control circuit 310 of the visible light sensor 300) to process asensor event that includes detecting whether sunlight entering from awindow (e.g., the windows 104, 214) may be shining on (e.g., producingglare on) only a portion of a region of interest and if glare isdetected, to operate motorized window treatments (e.g., the motorizedwindow treatments 150) to eliminate the partial glare. For example, aregion of interest may be defined to be a desk surface within a room(e.g., the region of interest 262 in the room 200 shown in FIG. 2E). Thevisible light sensor may be configured to determine whether sunlight ispartially shining upon the surface of the desk and when present, toeliminate the glare by operating motorized window treatments. Accordingto this example, once obtaining the region of interest from a retrievedimage by applying a mask for that region to the image, the visible lightsensor may analyze the region of interest to determine if one or moreportions/sections of the region of interest have a different luminancethan one or more other portions of the region of interest and if so, maydetermine that glare is present at only a portion of the region.

The glare detection procedure 800 may start at step 810. At step 812,the visible light sensor may subdivide the region of interest into aplurality of sections, where each section includes a number of imagepixels. For example, assuming the region of interest is the shape of asquare, the visible light sensor may subdivide the square into numeroussub-squares. The number of sections a region of interest is subdividedinto may be a function of a size or area of the region of interest asdetermined by the visible light sensor. At step 814, the visible lightsensor may compute the luminance of each section. The visible lightsensor may determine the luminance of each section by computing theluminance of each pixel (or a subset of pixels) that makes up a givensection and then integrating or averaging these computed values into asingle luminance value, which may be obtained as described previously.

Once having a computed luminance value for each section, the visiblelight sensor 180 may compare the luminance values of the sections atstep 816 to determine whether one or more sections have computedluminance values that differ from one or more other sections by athreshold value (e.g., by a factor of four although other factors may beused). At step 818, the visible light sensor may determine whether oneor more sections have differing luminance values. If so, the visiblelight sensor may communicate one or messages for causing the motorizedwindow treatments to lower the window treatment fabric at step 820. Theamount by which by the window treatment fabric is lowered may be afunction of the number of sections determined to have differingluminance values. On the contrary, if one or more sections aredetermined to not have differing luminance values, the glare detectionprocedure 800 may end with visible light sensor not modifying the levelof the window treatment fabric.

FIG. 9 is a flowchart of another example glare detection procedure 900,which may be executed by a control circuit of a visible light sensor(e.g., the control circuit 310 of the visible light sensor 300) toprocess a sensor event that includes detecting whether sunlight enteringfrom a window (e.g., the window 104) may be shining on (e.g., producingglare on) all of or at least a portion of a region of interest and ifglare is detected, to operate motorized window treatments (e.g., themotorized window treatments 150) to eliminate the glare. Again, as anexample the region of interest may be defined to be a desk surfacewithin a room (e.g., the region of interest 262 in the room 200 shown inFIG. 2E). According to this example, once obtaining the region ofinterest from a retrieved image by applying a mask for that region tothe image, the visible light sensor may analyze the region of interestto determine whether a computed luminance value for the region ofinterest exceeds a baseline luminance value and if so, may determinethat glare is present on at least a portion of the region.

The glare detection procedure 900 may start at step 910. At step 912,the visible light sensor may determine a luminance value for the regionof interest by computing a luminance value for each image pixel makingup the region of interest (e.g., as described above) and thenintegrating or averaging these computed values to obtain a singleluminance value for the region of interest. At step 914, the visiblelight sensor may compare the computed luminance value for the region ofinterest to a baseline luminance value determined for the region ofinterest. At step 916, the visible light sensor may determine whetherthe computed luminance value exceeds the baseline luminance value by athreshold value (e.g., by a factor of four although other factors may beused). If the computed luminance value exceeds the baseline luminancevalue by the threshold value, at step 918 the visible light sensor maycommunicate one or messages to the motorized window treatments to lowerthe window treatment fabric. The amount by which by the window treatmentfabric is lowered may be a function of the amount by which the computedluminance value exceeds the baseline luminance value. On the contrary,if the computed luminance value does not exceed the baseline luminancevalue by the threshold value, the glare detection procedure 900 may endwith visible light sensor not modifying the level of the windowtreatment fabric.

FIG. 10 shows a flowchart of an example configuration procedure 1000 fora visible light sensor (e.g., the visible light sensor 180 and/or thevisible light sensor 300) using a special configuration software. Theconfiguration software may be used in a way that protects the privacy ofthe users of a space (e.g., the room 102 and/or the room 200). Thevisible light sensor may be configured to transmit digital messages viaa first communication link (e.g., a communication link using aproprietary protocol) during normal operation. The configurationprocedure 1000 may begin at step 1010. At step 1012, the visible lightsensor may be installed, for example, on a ceiling, a wall, and/or anyother location in which it may be useful to install the visible lightsensor. Configuration software may be installed on a visible lightsensor at step 1014. The configuration software may allow the visiblelight sensor to transmit an image recorded by a camera (e.g., the camera322) via a second communication link (e.g., a communication link using astandard protocol) during configuration of the visible light sensor. Theconfiguration software may be installed in memory (e.g., the memory 312)during manufacturing, such that the visible light sensor is ready to beconfigured when powered after installation. The visible light sensor mayalso be configured to receive the configuration software via the secondcommunication link) and the visible light sensor may store theconfiguration software in the memory during configuration of the visiblelight sensor.

At step 1018, the visible light sensor may transmit the image of thespace, for example, to a network device (e.g., the network device 190)via the second communication link. At step 1020, the transmitted imagemay be displayed, for example, on a graphical user interface (GUI) on avisual display of the network device. At step 1022, a user of thenetwork device may configure the operation of the visible light sensor,for example, using the image received and displayed by the networkdevice. At step 1024, the network device may transmit the configurationparameters to the visible light sensor. Configuration parameters mayinclude, for example, desired sensor events, operational parameters forsensor events, digital masks and/or regions of interest for sensorevents, baseline images and/or values, etc. The configuration parametersmay be transmitted via the same, or different, protocol (e.g., the firstcommunication link) that was used to transmit the image at step 1018.

At 1026, the configuration software may be uninstalled from the visiblelight sensor, for example, when configuration of the visible lightsensor is complete. For example, when the configuration of the visiblelight sensor is complete, the visible light sensor may exitconfiguration mode and move to the normal operation mode of the visiblelight sensor for sensing environmental characteristics from the recordedimages and transmitting messages for load control. At step 1028, normaloperation software may be installed by the visible light sensor for useduring normal operation of the visible light sensor. The normaloperation software may be installed in the memory of the visible lightsensor and/or may be received via the first or second communicationlinks during configuration of the visible light sensor. The normaloperation software may include the normal operation modes (e.g., thesensor modes) for sensing environmental characteristics from therecorded images and transmitting messages for load control.

FIG. 11 shows a flowchart of an example configuration procedure 1100 fora visible light sensor (e.g., the visible light sensor 180 and/or thevisible light sensor 300) using a removable configuration module. Thevisible light sensor may be configured to transmit digital messages viaa first communication link (e.g., a communication link using aproprietary protocol) during normal operation. During configuration ofthe visible light sensor, the configuration module may be coupled to(e.g., installed in) the visible light sensor. When the configurationmodule is installed in the visible light sensor, a control circuit(e.g., the control circuit 310) may transmit an image recorded by acamera (e.g., the camera 322) via a second communication link (e.g., acommunication link using a standard protocol). The configuration modulemay be removed from the visible light sensor, resulting in the visiblelight sensor being unable to transmit images.

The configuration procedure 1100 may begin at step 1110. At 1112, thevisible light sensor may be installed, for example, on a ceiling, awall, and/or any other location in which it may be useful to install thevisible light sensor. At 1114, a module may be coupled to the visiblelight sensor. The module may have one or both of wired and wirelesscapabilities (e.g., for transmitting wireless signal via the secondcommunication link). When the configuration module is installed in thevisible light sensor and the configuration module is electricallycoupled to the visible light sensor, the visible light sensor may recordan image of the space and transmit the image to a network device (e.g.,the network device 190), for example, directly to the network device viathe second communication link. As step 1120, the network device maydisplay the image, for example, on a graphical user interface (GUI) on avisual display of the network device.

At 1122, a user of the network device may configure the operation of thevisible light sensor, for example, using the image received anddisplayed by the network device. Configuration parameters may include,for example, desired sensor events, operational parameters for sensorevents, digital masks and/or regions of interest for sensor events,baseline images and/or values, etc. At step 1124, the network device maytransmit the configuration parameters to the visible light sensor whilethe configuration module is still installed in the visible light sensor,and the visible light sensor may store the configuration information inmemory. After the configuration of the visible light sensor is complete,the configuration module may be removed from the visible light sensor atstep 1126. With the configuration module removed, the visible lightsensor may be unable to transmit images via the second communicationlink. The configuration module may remain disconnected from the visiblelight sensor during normal operation of the visible light sensor.

FIG. 12 shows a flowchart of an example configuration procedure 1200 fora visible light sensor (e.g., the visible light sensor 180 and/or thevisible light sensor 300) using a special configuration sensor. Thevisible light sensor may be configured to transmit digital messages viaa first communication link (e.g., a communication link using aproprietary protocol) during normal operation. The configuration sensormay have a structure that is identical, or similar, to the visible lightsensor. However, the configuration sensor may be configured to transmitdigital messages via a second communication link (e.g., a communicationlink using a standard protocol) during the configuration procedure. Theconfiguration sensor may be configured to transmit images of the spacevia the second communication link.

The configuration procedure 1200 may begin at step 1210. At 1212, theconfiguration sensor may be installed, for example, in place of thevisible light sensor. At step 1214, the configuration sensor may recordan image of the space, for example, using a camera. At step 1216, theconfiguration sensor may transmit the image of the space, for example,to a network device (e.g., the network device 190) via the secondcommunication link. At step 1218, the transmitted image may bedisplayed, for example, on a graphical user interface (GUI) on a visualdisplay of the network device. At 1220, a user of the network device mayconfigure the operation of the visible light sensor, for example, usingthe image received and displayed by the network device. Configurationparameters may include, for example, desired sensor events, operationalparameters for sensor events, digital masks and/or regions of interestfor sensor events, baseline images and/or values, etc.

At 1222, the configuration sensor may be uninstalled, for example, whenconfiguration of the visible light sensor is complete. For example, thevisible light sensor may exit the configuration mode and move to thenormal operation mode of the visible light sensor when the configurationof the visible light sensor is complete. At step 1224, the visible lightsensor (e.g., that is not configured to communication on the secondcommunication link) may be installed in place of the configurationsensor. At step 1226, the network device may transmit the configurationparameters to the visible light sensor. For example, the visible lightsensor may receive configuration information via the first communicationlink and may store the configuration information in memory.

What is claimed is:
 1. A sensor for sensing an environmentalcharacteristic of a space, the sensor comprising: a visible lightsensing circuit configured to record an image of the space; a low-energyoccupancy sensing circuit configured to detect occupancy conditions inthe space; and a control circuit configured to disable the visible lightsensing circuit when the space is vacant, the control circuit configuredto detect an occupancy condition in the space in response to thelow-energy occupancy sensing circuit and to subsequently enable thevisible light sensing circuit.
 2. The sensor of claim 1, wherein thecontrol circuit is configured to detect that a vacancy condition in thespace in response to the visible light sensing circuit.
 3. The sensor ofclaim 2, wherein the control circuit is configured to disable thevisible light sensing circuit after detecting the vacancy condition inthe space.
 4. The sensor of claim 1, further comprising: a communicationcircuit configured to transmit and receive digital messages; wherein thecontrol circuit is configured to transmit a digital message indicatingthe occupancy condition via the communication circuit after detectingthe occupancy condition in the space in response to the low-energyoccupancy sensing circuit.
 5. The sensor of claim 4, wherein the controlcircuit is configured to transmit a second digital message indicating avacancy condition via the communication circuit after detecting thevacancy condition in the space in response to the visible light sensingcircuit.
 6. The sensor of claim 1, wherein the control circuit isconfigured to detect that the occupancy condition is maintained in thespace in response to the visible light sensing circuit.
 7. The sensor ofclaim 1, wherein the low-energy occupancy sensing circuit comprises apassive infrared sensing circuit.
 8. The sensor of claim 1, wherein thevisible light sensing circuit comprises a camera and an image processor.9. The sensor of claim 1, wherein the environmental characteristiccomprises a movement, a light intensity, a color temperature, theoccupancy condition, or a vacancy condition.
 10. The sensor of claim 1,wherein the control circuit is configured to: detect the occupancycondition in the space while in an occupancy/vacancy mode; and based ondetecting the occupancy in the space, transmit a message to a loadcontrol device to adjust a light intensity presented by the load controldevice.
 11. A method for sensing an environmental characteristic of aspace, the method comprising: recording an image of a space via avisible light sensing circuit; disabling the visible light sensingcircuit when the space is determined to be vacant; detecting anoccupancy condition in the space via a low-energy occupancy sensingcircuit; and enabling the visible light sensing circuit in response tothe occupancy condition detected via the low-energy occupancy sensingcircuit.
 12. The method of claim 11, further comprising: detecting avacancy condition in the space in via the visible light sensing circuit.13. The method of claim 12, wherein the visible light sensing circuit isdisabled after the vacancy condition is detected in the space.
 14. Themethod of claim 11, further comprising: transmitting a digital messageindicating the occupancy condition after detecting the occupancycondition in the space in response to the low-energy occupancy sensingcircuit.
 15. The method of claim 14, further comprising: transmitting asecond digital message indicating a vacancy condition after detectingthe vacancy condition in the space in response to the visible lightsensing circuit.
 16. The method of claim 11, further comprising:detecting that the occupancy condition is maintained in the space inresponse to the visible light sensing circuit.
 17. The method of claim11, wherein the low-energy occupancy sensing circuit comprises a passiveinfrared sensing circuit.
 18. The method of claim 11, wherein thevisible light sensing circuit comprises a camera and an image processor.19. The method of claim 11, wherein the environmental characteristiccomprises a movement, a light intensity, a color temperature, theoccupancy condition, or a vacancy condition.
 20. The method of claim 11,further comprising: detecting the occupancy condition in the space whilein an occupancy/vacancy mode; and based on detecting the occupancycondition in the space, transmitting a message to a load control deviceto adjust a light intensity presented by the load control device.